辐射感生应力弛豫对Al_mGa_(1-m)N/GaN HEMT电学特性的影响  

The effect of radiation induced strain relaxation on electric performance of Al_mGa_(1-m) N/GaN HEMT

作　　者：范隆[1] 郝跃[2] 

机构地区：[1]北京时代民芯科技有限公司,北京100076 [2]宽禁带半导体材料与器件教育部重点实验室,西安电子科技大学,西安710071

出　　处：《物理学报》2007年第6期3393-3399,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划项目(批准号:2002CB3119)资助的课题~~

摘　　要：基于电荷控制原理建立了辐射感生AlmGa1-mN势垒层应力弛豫对AlmGa1-mN/GaN HEMTs器件电学特性影响的解析模型,并进行了仿真分析.结果表明,对于高Al组分HEMTs器件,AlmGa1-mN势垒层中辐射感生的应力弛豫影响更为显著.辐射感生应力弛豫不但导致2DEG下降和阈值电压正向漂移,而且能够引起漏极输出电流的明显下降.辐射感生应力弛豫是赝配AlmGa1-mN/GaN HEMTs辐射损伤的重要机理之一.A complete model for studying the effect of radiation induced strain relaxation on electric performance of AlGaN/GaN HEMT was built utilizing the degree of strain relaxation related to radiation dose and energy as a basic variable. The effects of radiation induced strain relaxation on carrier density, threshold voltage and I-V characteristic were systematically investigated. The calculation results indicated that decrease in polarization induced charges as a result of strain relaxation causes decrease in carrier density, increase in threshold volgate and degradation in saturation drain current according to a linear rule. All results showed that the effect of radiation induced strain relaxation on HEMTs with high Al content appears more prominent. The calculation results also imply that strain relaxation is one of the important radiation damage mechanisms, the sensitivity of Al content to radiation induced strain relaxation degree need to be considered when improving the figure of merit of HEMTs by virtue of enhancement in Al content.

关 键 词：AlmGa1-mN/GaN HEMT 辐射损伤 应力弛豫 

分 类 号：TN322[电子电信—物理电子学]